Forests 2022 , 13 , 1856
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equipment during the whole life cycle transportation of paper products are not included in the accounting system because of the difficulty in obtaining data. (2) In terms of accounting methods, when accounting for CO 2 emissions from domestic waste paper recycling in the transportation stage, it is assumed that the waste paper generated in each of the 16 major paper and paperboard-producing provinces is recycled for pulping within the province, and the distance of this part of waste paper recycling is 0, resulting in negligible CO 2 emissions; the waste paper from the remaining 15 (non-major paper and paperboard producing) provinces is recycled and transported to the nearest major paper and paperboard producing province (region or city), and the distance between the provincial capitals of the two provinces is taken as the distance of waste paper recycling, which may be slightly lower than the actual transportation distance, resulting in lower CO 2 emissions from waste paper recycling and transportation. (3) Some data parameters (such as CO 2 emissions coefficients of different transportation modes) are adopted from relevant European research data, while there are certain differences between the development of China and Europe, which will affect the accuracy of the relevant parameters used. In addition, this paper sets theCO 2 emissions coefficients related to each stage of the study period unchanged, but the corresponding CO 2 emissions coefficients may decrease with the improvement of the technology level in various aspects, which will lead to some errors in the accounting results. (4) Regarding the accounting method of CO 2 emissions used, there are relevant references forCO 2 emissions accounting methods listed in our paper. Among similar studies, CO 2 emissions accounting studies from the perspective of different pulp types are relatively consistent with the results of this paper [7,27]. In addition, the CO 2 emissions trend of the papermaking industry in this article is consistent with the overall situation of CO 2 emissions of the manufacturing industry in China [54], while reflecting the industrial characteristics of low carbon development, transformation, and upgrading of the papermaking industry. 4. Forecast of LCA CO 2 Emissions Scenarios for Paper Products in China Since the pulp and paper and waste paper disposal stage is the main stage of the whole life cycle of CO 2 emissions of paper products, reduction in CO 2 emissions in the process of pulp and paper and waste paper disposal is the key link to low carbon development of paper products in China. Accordingly, this paper further predicts the whole life cycle of CO 2 emissions of paper products in China from 2020 to 2035 using scenario analysis. Among them, the baseline scenario uses curve fitting to predict CO 2 emissions at each stage of the whole life cycle of paper products, i.e., CO 2 emissions are predicted for each stage of the whole life cycle, and then aggregated into the total CO 2 emissions of the whole life cycle of paper products. Low-carbon scenario I only improves the waste paper recovery rate, otherwise the same as the baseline scenario; low-carbon scenario II only improves the energy consumption structure in the pulp and paper stage, otherwise the same as the baseline scenario; low-carbon scenario III improves both the energy structure and waste paper recovery rate, otherwise the same as the baseline scenario. In terms of scenario parameters, the paper recycling problem is complex and comprehensive, which is reflected in the fact that paper recycling cannot achieve a high recycling rate under the existing circumstances due to the economic structure, paper characteristics, and recycling algorithms in China. In this paper, we set the optimization criteria in the scenario prediction by combining the policy proposal and the impact of the “waste separation” policy on CO 2 emissions in the waste paper disposal stage. Low carbon scenario I sets China’s waste paper recycling rate to 74% in 2035 with reference to Europe’s waste paper recycling rate of 74% in 2020, and assumes a linear increase in the waste paper recycling rate from 2020 to 2035. For the low carbon scenario II, with reference to the requirements in the outline of the “14th five-year plan” and the 2035 visionary goals for national economic and social development of the People’s Republic of China issued by the National Development and Reform Commission, the proportion of non-fossil energy consumption in 2035 is set to be about 20% [55], the proportion of coal consumption is within 49%, natural gas is more than 13%, and oil is about 16% [56]. The total energy consumption of the papermaking industry
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